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邻苯二甲酸酯(PAEs)作为增塑剂广泛用于制造和加工塑料产品。PAEs的生产始于20世纪20年代,其用量一直在增长[1-3]。PAEs在制造、使用和处置过程中可以直接或间接地释放到环境中。PAEs普遍存在于大气气溶胶[4-5]、污水和废水处理的污泥[6]、河流和海水/沉积物[7]、饮用水[8]、生物群和空气[9]中。据报道,人类对 PAEs的摄入量可高达70 μg·(kg·d)−1;PAEs对生态系统功能和公共健康存在潜在影响,因而PAEs已引起广泛的关注[10]。短链酯(如邻苯二甲酸二甲酯(DMP))是不同环境介质中最常见的PAEs,作为一种内分泌干扰化学物质,其可能导致人类白细胞的染色体损伤,干扰动物和人类的生殖系统和正常生长发育[11]。因此,研发一种可用于从水域和废水中去除这种污染物的处理技术十分必要。
去除DMP的方法包括催化臭氧法[12],γ-辐射/ H2O2工艺[13],紫外光催化法[14],生物降解处理法[15]等。在众多处理方法中,光催化技术已被证明能够有效处理各种水体污染物。高铁酸钾作为一种高效的电子受体可有效抑制e−/h+重组,其还原产物为Fe3+或Fe(OH)3, 具有絮凝、吸附、共沉淀等功能,是一种绿色氧化剂,但目前关于高铁酸盐和光催化组合降解有机水污染物的研究相对较少。
本研究利用高铁酸钾与TiO2光催化的协同氧化效应降解水中DMP,建立了DMP降解方法,并探究了不同参数对DMP降解效果的影响以及反应过程中在催化剂表面产生Fe—O—(有机)络合物对降解效果的影响。
Dimethyl phthalate degradation by TiO2-UV photo-catalysis process combined with K2FeO4
- Received Date: 15/11/2018
- Available Online: 01/10/2019
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Key words:
- photocatalysis /
- dimethyl phthalate(DMP) /
- titanium dioxide /
- ferrate
Abstract: Due to the refractory characteristics of dimethyl phthalate (DMP), a combined ferrate-photocatalysis process was used to degrade the DMP in aqueous solution. The effects of different parameters on DMP degradation were studied and the corresponding photo-catalytic degradation mechanism was also investigated. The results shows that the DMP degradation rate by Fe(VI)-TiO2-UV system was significantly better than those of the other two systems(ferrate alone and TiO2-UV), which indicated that the remarkable synergistic effects occurred in the combination of photocatalysis and ferrate. Specifically, when DMP initial concentration was 5 mg·L−1 and pH was 9, the doses of ferrate and titanium dioxide were 31.7 mg·L−1 and 40 mg·L−1, respectively, the DMP degradation rate DMP could reach 75%. During the DMP photodegradation by Fe(Ⅵ)-TiO2-UV system, the Fe—O—(organic) complexes produced on the surface of TiO2 could inhibit its degradation, but the TiO2 activity can be regenerated by washing with 1% HCl solution. For the actual production wastewater and simulated wastewater, the DMP degradation rates with Fe(Ⅵ)-TiO2-UV system were 67% and 78.2%, respectively. The synergistic effect of the combined ferrate-photocatalysis process greatly improved the DMP degradation rate.